Axially arranged rotary threshing or separating systems have long been in use in agricultural combines for threshing crops to separate grain from crop residue, also referred to as material other than grain (MDG). Such axially arranged systems typically include at least one cylindrical rotor rotated within a concave or cage, with the rotor and surrounding concave being oriented so as to extend forwardly to rearwardly within the combine.
In operation, crop material is fed or directed into a circumferential passage between the rotor and the concave, hereinafter ref erred to as a rotor residue passage, and is carried rearwardly along a generally helical path in such passage by the rotation of the rotor as grain is threshed from the crop material. The flow of crop residue or MDG remaining between the rotor and concave after threshing is typically discharged or expelled by the rotating rotor at a rear or downstream end of the rotor and the rotor residue passage in a generally downward, or a downward and sidewardly, direction in what is a continuation of the helical path of movement of the crop residue within the rotor residue passage between the rotor and concave.
The flow is typically discharged into a discharge opening at the downstream end of the rotor and into a further passage, hereinafter referred to as a discharge passage or discharge chute, that extends downwardly and somewhat rearwardly into a crop residue distribution system located below and rearwardly of the rear end of the threshing system, which crop residue distribution system typically includes a laterally disposed rotary beater or chopper that beats or chops the crop residue into smaller pieces and propels the resulting chopped crop residue rearwardly within a rear end of the combine for either discharge from the combine through a rear opening onto a field or introduction into a residue spreader apparatus, which residue spreader apparatus may include a further chopper and/or spreader, mounted on the rear end and operable for spreading the residue over a swath of a field.
Due to the nature of operation of the threshing rotor, the design of such rotor and concave, and the helical movement of the crop residue within the rotor residue passage, the resulting flow of crop residue from the rotor residue passage into the discharge opening is often greater on the downward sweep side of the rotor than on the upward sweep side, as a consequence of which an uneven flow of crop residue is presented across the width of the discharge opening and so introduced into the beater or chopper. Such uneven input flow has typically, in the past, resulted in inefficient operation of the beater or chopper, uneven wear of components of the beater or chopper, and poor material conveyance from the beater or chopper to the residue spreader apparatus at the rear of the harvester.
Since the flow of crop residue as introduced into the beater or chopper is often considerably heavier at one side of the beater or chopper, the crop mat introduced into the beater or chopper is often too thick for the beater or chopper to effectively handle, as a consequence of which the chop quality of the residue discharged from the beater or chopper is often less than desirable. Because the components of the beater or chopper which are associated with the side of the beater or chopper that experiences such heavier flow are subjected to greater abuse, they wear more quickly, thus degrading the performance of the beater or chopper over time, especially on the side handling the heavier flow. As a consequence, the output flow of residue from the beater or chopper often exhibits both uneven chop quality and uneven distribution across the width of the beater or chopper, with the heavier concentration of the poorly chopped residue remaining concentrated along the side of heavier flow from the threshing rotor as the crop residue proceeds toward the residue spreader. Such uneven flow across the width of the beater or chopper poses difficulties for the combine users.
Combine users desire, in many instances, when the crop residue is to be spread in a swath over a field, that the crop residue be distributed evenly or uniformly over the swath. Uniform distribution is desirable for a number of reasons. Included among such reasons are that uneven crop residue distribution on a field can lead to temperature and moisture gradients detrimental to even growth of future crops on the field, uneven distribution can make it difficult for crops to utilize nutrients, and uneven distribution can impact the effectiveness of agricultural chemicals. In addition, the existence of large discontinuities of spread crop residue can lead to plugging and other functional problems when such discontinuities are encountered by tillage and/or planting equipment.
It has been recognized that one factor that affects the ability of a residue spreader to distribute crop residue evenly or uniformly over a field is the transverse or side to side evenness of crop residue inflow into the residue spreader. However, the side to side uniformity of the infeed to the residue spreader is directly related to the side to side uniformity of the output flow from the beater or chopper, and since such output flow is recognized to be a function of the side to side distribution of crop residue infeed into the beater or chopper from the threshing system, it is therefore desirable to be able to effect a relatively uniform distribution of crop residue across the width of the beater or chopper, or at least to be able to more evenly distribute the flow being discharged from the threshing rotor.
In light of the foregoing considerations, several devices and structures have been developed to try to improve and better distribute the flow of crop residue from axially arranged threshing systems into crop residue distribution systems, including constructions such as are disclosed in Payne et al. U.S. Pat. No. 6,352,474 entitled Metering Edge for Axially Arranged Rotary Separator, which discloses the use of a relatively thin projecting asymmetrical arcuate assembly adjacent approximately the lower half of the concave of the combine with a metering edge overhanging the discharge chute from the rotor residue passage into the beater or chopper, and Pfeiffer et al. U.S. Pat. No. 6,241,605 entitled Discharge Geometry for Axially Arranged Rotary Separator, which discloses use of a deflector at the downstream end of the threshing rotor that extends into the flow passageway and has a relatively thin and flexible free end with upper and lower metering edges for metering the flow of residue to a discharge chute with guide vanes for introduction into the beater or chopper.
Although the above referenced constructions may offer improved performance, they employ and require the use of metering edges as part of their constructions in attempts to obtain improved flow of crop residue. Moreover, the required metering edges of such constructions are subject to significant abuse, especially for heavy crop residue flows, and the relatively thin overhanging arcuate assembly of Payne et al. U.S. Pat. No. 6,352,474 and the relatively thin free end of the deflector in the construction of Pfeiffer et al. U.S. Pat. No. 6,241,605, due to their design characteristics, including their flexure characteristics as force is applied thereto, can be significantly affected in heavy flow situations and subject to damage or distortion if the rotor is caused to operate in reverse mode, such as in the event of a plugged condition.
Consequently, what has continued to be sought is a discharge deflector that can positioned to interact with the crop residue flow from the threshing rotor, that does not require metering edges, and which can better withstand the wear and tear of use without significant flexure or distortion in heavy flow situations or in the event of rotor reversals, to effect a better distribution of crop residue introduced onto the beater or chopper of an agricultural combine, which improved distribution can result in more efficient operation of the beater or chopper, better chop quality from the beater or chopper, and more even throughput of crop residue to the residue spreader.